Jing: Handy screen and video capture tool

First: Jing Techsmith gives you a free download.

Image via CrunchBase

1. Download.
2. Install.
3. Go Pro (costs $14/year, recommended)
4. Customize buttons (Add new buttons for FB, Flickr, etc)
5. Start to capture.

Techsmith also makes Snaggit (more capture, plus more editing) and Camtasia Studio.
I've used them all. They are all excellent. Well thought out. Easy. Always getting better.